Subscriber access provided by Purdue University Libraries
Article
A 320-year ice-core record of atmospheric Hg pollution in the Altai, Central Asia Stella Eyrikh, Anja Eichler, Leonhard Tobler, Natalia Malygina, Tatyana Papina, and Margit Schwikowski Environ. Sci. Technol., Just Accepted Manuscript • DOI: 10.1021/acs.est.7b03140 • Publication Date (Web): 18 Sep 2017 Downloaded from http://pubs.acs.org on September 19, 2017
Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.
Environmental Science & Technology is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.
Page 1 of 29
Environmental Science & Technology
1
A 320-year ice-core record of atmospheric Hg pollution in the Altai,
2
Central Asia
3 4
Stella Eyrikh1, Anja Eichler,2,3,*, Leonhard Tobler,2,3, Natalia Malygina1,
5
Tatyana Papina1, and Margit Schwikowski2,3,4 1
6
Institute for Water and Environmental Problems, Siberian Branch of the Russian Academy of Sciences,
7
Barnaul 656038, Russia 2
8 3
9 4
10
Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
Oeschger Centre for Climate Change Research, University of Bern, 3012 Bern, Switzerland
Department for Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
11 12 13 14 15 16
*
Corresponding author: e-mail:
[email protected], phone: +41 56 310 2077, fax: +41 56 310 4435
17 18 19
KEYWORDS: ice core, mercury, emission, Central Asia, Siberian Altai
20 21 22
ACS Paragon Plus Environment
1
Environmental Science & Technology
Page 2 of 29
23 24 25 26
TOC - Art
27
28 29
ACS Paragon Plus Environment
2
Page 3 of 29
30
Environmental Science & Technology
Abstract
31
Anthropogenic emissions of the toxic heavy metal mercury (Hg) have substantially increased atmospheric
32
Hg levels during the 20th century compared to pre-industrial times. However, on a regional scale, atmospheric
33
Hg concentration or deposition trends vary to such an extent during the industrial period that the
34
consequences of recent Asian emissions on atmospheric Hg levels are still unclear. Here we present a 320-
35
year Hg deposition history for Central Asia, based on a continuous high-resolution ice-core Hg record from
36
the Belukha glacier in the Siberian Altai, covering the time period 1680-2001. Hg concentrations and
37
deposition fluxes start rising above background levels at the beginning of the 19th century due to emissions
38
from gold/silver mining and Hg production. A steep increase occurs after the 1940s culminating during the
39
1970s, at the same time as the maximum Hg use in consumer products in Europe and North America. After a
40
distinct decrease in the 1980s, Hg levels in the 1990s and beginning of the 2000s return to their maximum
41
values, which we attribute to increased Hg emissions from Asia. Thus, rising Hg emissions from coal
42
combustion and artisanal and small-scale gold mining (ASGM) in Asian countries determine recent
43
atmospheric Hg levels in Central Asia, counteracting emission reductions due to control measures in Europe
44
and North America.
45
1. Introduction
46
Mercury (Hg) is one of the most studied and notorious global environmental pollutants that has been the
47
subject of particular attention of scientists and the public worldwide for many years. In October 2013, the
48
Minamata Convention on Mercury, aiming to protect human health and the environment from anthropogenic
49
emissions of the toxic heavy metal Hg, was established1. To date, over 50 countries have authorized the
50
convention and it became active on 16, August, 2017. Hg is released into the environment from natural
51
sources (e.g. mineral dust and volcanoes) and anthropogenic activities (e.g. fossil combustion, gold and silver
52
mining, see Fig. 1). Due to the long residence time of its elemental form (Hg0, ~1 year), representing as much
ACS Paragon Plus Environment
3
Environmental Science & Technology
Page 4 of 29
53
as 95% of the atmospheric Hg burden2, Hg can be distributed globally via the atmosphere or oceans. Thus,
54
ecosystems far away from anthropogenic emission sources can be contaminated after long-range transport of
55
Hg0, oxidation to Hg2+, and input by wet or dry deposition3.
56
Understanding how the legacy of past anthropogenic emissions contributes to present-day Hg enrichment is
57
essential for anticipating the effectiveness of future reductions in Hg emissions4. However, large uncertainties
58
exist in quantifying the fluxes in the Hg biogeochemical cycle, particularly regarding natural and
59
anthropogenic emissions to the atmosphere, deposition and re-emissions5, 6. Hg concentrations in air and wet
60
deposition have been measured since 1990 at selected sites mainly in the Northern Hemisphere7, 8, whereas a
61
coordinated observing system to monitor Hg on a global scale started only in 20109. Natural archives provide
62
the long-term history of atmospheric Hg deposition. Studies of lake and marine sediments10-14, peat bogs15-17
63
and ice-cores18-23 resulted in a general consensus that anthropogenic emissions during the 20th century have
64
substantially increased atmospheric Hg levels compared to pre-industrial times. Whereas emission estimates
65
suggest that Hg emissions from wide-spread coal burning and artisanal, small-scale gold mining (ASGM) in
66
Asia have recently outpaced those from commercial Hg use in the last decades24, the corresponding Hg
67
profiles from natural archives do not show such a clear picture. In sediment and ice core records from North
68
America and Europe, Hg peaks in the mid- to late 1900s and decreases afterwards due to reduced recent
69
anthropogenic Hg emissions in these industrialized regions10, 19, 25-29. This is consistent with a 20-38% decline
70
in atmospheric Hg concentrations from 1995 to 2009 at different monitoring stations in the Northern and
71
Southern Hemisphere7. In contrast, sediment records from remote areas in the Arctic, Antarctic, and North
72
America reveal a continuous Hg increase towards the end of the 20th/ beginning of the 21th century12, 30-33.
73
This is also the case for most study sites in close proximity of Asian Hg source regions14, 20, but their majority
74
is lake sediments of the Tibetan Plateau, representing deposition histories with a very low resolution. The
75
latter is caused by low productivity and correspondingly low sedimentation rates at these high altitudes.
76
Further complicating is the finding, that such high recent values in lake sediments do not necessarily indicate
77
elevated emissions, but may partly be explained by rather local signals and polluted catchment soils34. To our ACS Paragon Plus Environment
4
Page 5 of 29
Environmental Science & Technology
78
knowledge, the only available long-term Asian high-resolution Hg record is from the Geladaindong ice core
79
(central Tibetan Plateau)20. This record shows an increasing trend since the 1940s similar to the lake
80
sediments, but ends too early (1982) to capture the recent period.
81
Here, we present a continuous high-resolution ice-core based Hg record from the Belukha glacier in the
82
Siberian Altai, covering the time period 1680-2001. This new ice-core record fills the data gap for continental
83
Central Asia and allows assessing the influence of anthropogenic emissions from industrial Hg use in Europe
84
and North America and of recent emissions from coal burning and ASGM in Asia. The obtained Hg results
85
are discussed with respect to estimates of historical atmospheric Hg emissions and compared with other ice
86
core records in Europe, North America, the Arctic, and Asia.
87
2. Experimental section
88
2.1. Study site characteristics and ice core dating
89
In July 2001 a 139 m ice core was drilled at the saddle between the two summits of the Belukha
90
(49°48’26’’N, 86°34’43’’E, 4062 m a.s.l.), the highest mountain in the Altai region (4506 m a.s.l.)35 (Fig. 2).
91
Low constant englacial temperatures of -17ºC (below 15 m depth) indicate that the glacier site belongs to the
92
cold infiltration recrystallization zone, where meltwater formed under the influence of solar radiation and
93
high air temperature refreezes some centimeters below the surface35. The main precipitation season in the
94
Altai is summer, with humid air masses from the Atlantic Ocean and recycled moisture from Central Asian
95
sources being the major sources of precipitation36. Winter months (December–February) receive less than 5%
96
of the annual precipitation, due to the prevailing stable Siberian High and the predominance of cold and dry
97
arctic air masses37. The ice core chronology was obtained by: 1) nuclear dating using the radioactive decay of
98
210
99
reference horizons related to the maximum of nuclear weapons testing (tritium and plutonium horizon in
Pb, 2) annual-layer counting of seasonal varying signals37,
41
38
and 3) a nonlinear regression39 through
100
1963)40 and several explosive volcanic eruptions38,
101
(93.7 m water equivalent (w.eq.)) of the Belukha core investigated in this work cover the period 1680-2001
(see Supplementary Information). The upper 113 m
ACS Paragon Plus Environment
5
Environmental Science & Technology
Page 6 of 29
102
(Fig. S1) with a mean annual accumulation rate of 0.56 m w.eq. The dating uncertainty is ±3 years for the
103
period 1815-2001 and ±5 years between 1680 and 1815.
104
The Belukha ice core has already been proven to contain well-preserved records of biogenic and biomass
105
burning tracers, anthropogenic pollutants, and water stable isotopes allowing to reconstruct temperature
106
changes in the Siberian Altai over the past 750 years37, 41, the history of biogenic emissions and forest fires
107
from Siberian forests42, 43, past anthropogenic emissions of NH3, NOx, SO2, and heavy metals from Eastern
108
Europe, the former Soviet Union and the Rudny Altai (Russian for ore Altai, Fig. 2)38, 44, 45. In the case of
109
such aerosol-related air pollutants with short atmospheric life-times of ~7 days source areas are regional as
110
indicated by 7-day air mass back-trajectories44. This is different for the long-lived Hg. Due to the atmospheric
111
life time of ~1 year, emission sources relevant for the study site are not restricted to European and Soviet
112
Union regions, but are assumed to be globally distributed.
113
2.2. Sample preparation
114
Ice-core sections (up to 0.7 m long, diameter 7.8 cm) were sealed in polyethylene tubes in the field and
115
transported frozen to the Paul Scherrer Institute (PSI, Switzerland) for glaciochemical analyses. 671 samples
116
of ice and firn were prepared for Hg analyses in the cold room of the PSI at -20°C. Due to annual layer
117
thinning with depth, sample resolution of the continuous record varied between one sample per year in the
118
deepest core sections (period 1680-1735) and 5-8 samples per year in the upper part of core (period 1940-
119
2001). 8% of the core could not be analyzed due to poor ice quality (small chips)44. Details of ice core cutting
120
and the decontamination procedure are described elsewhere45, 46. In brief, for the analysis of Hg only pristine
121
inner parts of the core (~2x2 cm) were cut out using a band saw. In a second step, contamination from the
122
saw blade and handling were removed by rinsing ice samples with ultrapure water (18 MΩ cm quality) and
123
by chiseling firn samples with a ceramic knife. The decontaminated samples for Hg analysis were placed in
124
Duran® glass bottles, oxidized to Hg(II) with BrCl solution according to US EPA 163147 and melted at room
ACS Paragon Plus Environment
6
Page 7 of 29
Environmental Science & Technology
125
temperature under class-100 clean room conditions at least 24 hour before analysis. Laboratory blanks were
126
regularly monitored using frozen ultra-pure water subjected to the same preparation steps.
127
All materials, equipment, and labware were pre-cleaned46 and tested for Hg contamination and preservation.
128
Glass bottles were pre-cleaned with a 0.5% BrCl solution, rinsed three times with ultrapure water and
129
subsequently filled with a 0.05 % HCl solution. Chemical reagents were either ultra-pure or Hg-free. All
130
analytical works were carried out following the protocol for ultra-clean condition for the determination of
131
ultra-low levels of Hg in ice and snow samples48, and according to US EPA 1631 method47.
132
2.3. Hg analysis
133
Hg concentrations (total Hg) were determined by Atomic Fluorescence Spectrometry (Mercur Analyser,
134
Analytik Jena, Germany). Calibration of the instrument was performed using at least 6 ultra-low
135
concentrations standards ranging from 0.2 to 100 ng L-1. Analytical accuracy was verified by determining Hg
136
concentrations in a certified reference material (Hg in river water, ORMS-2, Natural Research Council
137
Canada) (Table S1) and by standard addition to real firn and ice samples. The recovery was 98-102% and the
138
reproducibility 1-6%49, 50. The limit of detection (LoD) calculated as 3σ of 10 blanks as well as laboratory
139
blanks (including Hg contribution from water, reagent, containers, and air) were determined for each batch of
140
samples (28 batches). Concentrations of Hg in the firn and ice samples were blank-corrected by subtracting
141
the laboratory blank. The average laboratory blank from all batches was 0.31 ± 0.04 ng L-1and the average
142
LoD 0.04 ng L-1.
143
2.4. Hg flux calculations
144
Annual Hg fluxes were calculated by multiplying the mean annual Hg concentration with the respective
145
accumulation rate (in m w.eq.). Since annual layers were identified only for the period 1815-2001, a mean
146
accumulation rate of 0.56 m w.eq. was used for the flux calculations for the period 1680-1814 (see
147
Supplementary Information).
ACS Paragon Plus Environment
7
Environmental Science & Technology
Page 8 of 29
148
3. Results and Discussion
149
Hg concentrations of the 671 individual samples range from 0.07 to 8.9 ng L-1 with a median of 0.89 ng L-1
150
(Table 1). Concentration levels are in the same order of magnitude as reported for firn and ice cores from the
151
European Alps, Canadian Arctic, Tibetan Plateau, and Greenland (Table 1). This finding indicates that Hg
152
levels in the Altai are dominated by global Hg emissions and long-range transport, in accordance with the
153
long life-time of elemental mercury of ~1 year.
154
Hg deposition rates in the most recent samples (years 2000-2001) of 1.1 ± 0.2 µg m-2 a-1 are in reasonable
155
agreement with that of precipitation at rural Central Asian sites between 2012 and 2014 (2 ± 1.6 µg m-2 a-1)51.
156
Thus, we assume that major parts of the deposited Hg at the study site are preserved and not lost by possible
157
postdepositional processes, such as photoreduction, reemission, and meltwater relocation52-54. This is most
158
likely related to the formation of ice layers in the firn by refreezing of meltwater formed at the surface in
159
summer. These impermeable ice layers of rarely more than 2 cm thickness efficiently seal the firn layers
160
below from interacting with the atmosphere. Because of very cold ice temperatures of -16.6°C at 15 m depth,
161
melting and refreezing does not affect more than an annual layer and does not result in runoff. Accordingly
162
relocation of Hg in the firn layer is limited to within an annual layer, which is not relevant when discussing
163
10-year means.
164
The concentration record of Hg is presented in Figure 3. Annual averages were calculated from the raw
165
data to account for the varying sample resolution. The annual Hg concentration record reveals two distinct
166
features; namely short-term maxima with the most pronounced ones in 1843, 1884, and 1894, and a long-
167
term trend. Some of the brief Hg events occur synchronously with increases in Ca2+ or exSO42-
168
concentrations, indicating that they can be linked to an input of mineral dust aerosols from Central Asia
169
deserts or to emissions from volcanic events (see section 3.1., Fig. 3). To extract the long-term trend, annual
170
Hg data were averaged over 10-year periods (Fig. 3), after removing the dust and volcanic related spikes
171
depicted in Fig. 3. Hg concentrations start rising above background levels at the beginning of the 19th century,
172
followed by a steep increase after the 1940s and reach their maximum values during the 1970s. After a ACS Paragon Plus Environment
8
Page 9 of 29
Environmental Science & Technology
173
distinct decrease in the 1980s, Hg levels in the 1990s and beginning of the 2000s return to their maximum
174
values. This trend is not caused by changing accumulation rates, as demonstrated by the good agreement
175
between records of Hg concentrations and fluxes (see Fig. 4).
176
3.1. Short-term Hg maxima from mineral dust and volcanic events
177
Natural sources include Hg released from the Earth’s crust by weathering of Hg-containing rocks and Hg
178
emitted by volcanic eruptions and geothermal activity; however this contribution of geogenic sources has
179
large uncertainties on a global and regional level5. Vast arid zones in Central and South Asia are key mineral
180
dust sources in the Northern Hemisphere55. Numerous studies of Hg in snow and glacier ice from the Tibetan
181
Plateau showed that dust storms are a significant source of Hg deposition in this region54, 56, 57. Likewise, 7 of
182
the 15 most pronounced Hg maxima of the Belukha record (in the years 1687, 1768, 1811, 1843, 1884, 1894,
183
1985) are accompanied by Ca2+ maxima indicative of dust input (see Fig. 3). Emissions from deserts in
184
Kazakhstan and China were already shown to have a considerable input on short-term concentration changes
185
of other heavy metals as Cd, Cu, Pb, Sb, and Zn44, 45. Additionally to the dust source of the Hg concentration
186
peak in 198558 an impact of the accident at the Tengiz oil field in June 1985 on the high Hg concentrations in
187
this year was discussed59.
188
Volcanic eruptions are known to release a significant amount of Hg to the atmosphere, accounting for 20–
189
40% of natural emissions60. Short-term Hg peaks in an ice core from Upper Fremont Glacier in Wyoming
190
were associated with explosive volcanic events from the Northern and Southern Hemisphere23. This
191
attribution was challenged with the revised chronology of that record published recently61. In the Belukha
192
record the explosive volcanic eruptions in 1739 (Shikotsu), 1783 (Laki), 1815 (Tambora), and 1912 (Katmai)
193
are documented as the most prominent exSO42- maxima (Fig. 3,
194
concentrations. Only the Hg concentration maxima in 1726 and 1884 (Fig. 3) might be related to volcanic
195
input following the eruptions of Oraefojokul (1727) and Krakatao (1883). This finding suggests that only
44
), but are not accompanied by high Hg
ACS Paragon Plus Environment
9
Environmental Science & Technology
Page 10 of 29
196
selected volcanic eruptions leave an observable Hg imprint in remote natural archives, supporting the new
197
interpretation of the Upper Freemont ice core record61.
198 199
3.2. Long-time Hg trend 3.2.1. Pre-industrial period (1680-1850)
200
The pre-industrial time is characterized by low Hg concentrations and fluxes (median 0.47 ng L-1 and 0.32
201
µg m-2 a-1, respectively) (see Table 1), comparable with values reported for remote areas such as Greenland,
202
the Arctic and Antarctica21, 22, 62-64. Belukha Hg levels are rather low during the 17th and 18th century and start
203
rising at the beginning of the 19th century. Since the record starts only in 1680, it is ambiguous, whether the
204
low concentrations during 1680-~1810 represent natural background values, or are already influenced by
205
anthropogenic emissions.
206
The early 19th century rise in Hg could be from local or global sources. Although smelting of non-ferrous
207
metal ores provided a major Hg source already millennia ago65, the application of liquid Hg for silver and
208
gold mining, beginning ~1570 in Colonial Spanish South America, marked very likely the first global
209
distribution of anthropogenic Hg18,
210
European mines Almaden in Spain and Idrija in present-day Slovenia67. The estimated cumulative losses of
211
Hg to the environment due to the production of silver and gold in South America have been estimated at
212
196,000 t between 1580 and 1900, with an annual average of 612 t, peaking in the beginning of the 19th
213
century68 similar to the ice core record. Thus, during the pre-industrial period, silver and gold mining and Hg
214
production were worldwide the dominant Hg sources30, 69.
66
. The majority of Hg was extracted in Huancavelica (Peru) and the
215
Regionally, mining of precious metals and related metallurgical production began to develop in the Altai in
216
the first half of the 18th century. In the early 19th centuries 90% of the Russian silver was produced in the
217
Altai region as reflected by increased concentrations of Pb and other metals (Sb, Cd, Ag) in the ice core (see
218
Fig. 4, 44, 45, 70). In the first half of the 19th century all Russian silver and gold coins were manufactured in the
219
Altai. During that time amalgamation has not been used for silver and gold mining, but Hg was released to ACS Paragon Plus Environment
10
Page 11 of 29
Environmental Science & Technology
220
the atmosphere from high temperature smelting of gold- and silver-containing ores70, 71. The “Gold Rush”
221
occurred in Russia in 1828 after the discovery of numerous deposits of placer gold and the resolution of
222
private gold mining. Amalgamation was applied for the extraction of ore gold only in the Urals, whereas it
223
was not widely used in the Altai, Eastern Siberia and Transbaikal (mountainous region to the east of Lake
224
Baikal), where the most intensive extraction of placer gold was carried out72.
225
The steady increase in Hg from the beginning of the 19th century on is not due to changes in the deposition
226
regime or rising dust or volcanic input, since accumulation rates and frequency and strength of dust and
227
volcanic events remained constant (see Supplementary Information, Fig. 3). This interpretation is supported
228
by the fact that only Pb, Sb, and Hg show this early increase related to emissions from metallurgical
229
activities, whereas most of the trace elements such as Cu and Zn kept background levels45. A general change
230
in deposition regime should have affected all air pollutants.
231
The similarity in the Pb and Hg trends during the pre-industrial period suggests that the early increase of
232
the ice-core Hg levels in the first half of the 19th century is mainly related to regional emissions from the
233
metallurgy of precious metals for the production of Russian coins. An influence from early silver and gold
234
refining in South America is less likely, due to missing synchronous evidence from other ice core sites (Fig.
235
5), but cannot be ruled out.
236
3.2.2. Intermediate period (1850-1940)
237
During the intermediate period Hg concentrations and fluxes almost doubled compared to the pre-industrial
238
period (0.89 ng L-1 and 0.53 µg m-2 a-1, respectively), displaying a broad peak between the 1880s and 1930s.
239
This period is characterised by considerable Hg emissions from the gold/silver rush in Northern America.
240
Between 1850 and 1900 the mean annual Hg consumption in the United States was 1360 t; 90% were used
241
in the recovery of gold and silver68. Emission estimates for anthropogenic Hg by Streets et al.6 and
242
Horowitz et al.24 agree in the magnitude of the peak in 1890 (~2.6 kt/year) due to the gold/silver rush, but
243
differ for the major part of the 20th century. Streets et al.6 suggests that this first emission phase was
ACS Paragon Plus Environment
11
Environmental Science & Technology
Page 12 of 29
244
dominant, whereas according to the more recent, improved inventory by Horowitz et al.24, overall highest
245
Hg releases occurred during the 1970s (~3 kt/year) (see Fig. 1). Although our record agrees in general better
246
with the Horowitz et al.24 inventory, the 1880-1930 Hg peak is not as pronounced as the emission estimate
247
suggest (Fig. 4). This is in agreement with a large number of lake sediment records from remote sites30 and
248
the ice core data in Fig. 5. The discrepancy between the Hg emission estimates and the records from natural
249
archives is possibly due to an overestimation of gaseous Hg0 emissions from amalgamation. As shown in
250
recent studies73,
251
assumed to have partly surpassed that of Hg0 during that time. From the good correspondence between
252
world Hg production (mainly in North America, Spain, Italy, and Slovenia)67 and the ice core record in the
253
intermediate period (Fig. 4) we conclude that the ice core peak ~1880-1930 is not only due to direct Hg
254
emissions from gold and silver mining mainly in North America, but also to releases from worldwide Hg
255
production.
256
Local mining became less important in the intermediate period. At the end of the 1860s the mining and
257
metallurgical industry in the Altai entered a period of crisis due to the depletion of rich ore reserves and the
258
fall in silver prices. After 1870 the volume of the silver production decreased by a factor of two and until
259
1896 the majority of metallurgical plants were closed. At the same time coal mining started in the Kuznetsk
260
Basin, southwestern Siberia, in 1851 where some of the world's largest deposits of coal are located. Coal
261
production gradually increased from 17,000 tons in 1890 to 290,000 tons in 1904 (construction of the
262
Siberian railway), reaching 21,1 million tons in 194075. Generally, coal combustion is a major Hg source,
263
but emits also significant amounts of Pb76. Since ice-core Pb concentrations are not elevated after the 1890s
264
(Fig. 4), we assume that coal burning did not contribute to the elevated Hg levels in the intermediate period.
265
Likewise, the deviation between Hg and Pb records in the intermediate period suggests that the Hg peak
266
during ~1880-1930 is not dominated by enhanced emissions from regional metallurgy, but rather global
267
sources (see above) as corroborated by a synchronous increase at many sites18, 30, 61.
74
, releases of less volatile Hg2+ compounds calomel (HgCl2) and cinnabar (HgS) are
268 ACS Paragon Plus Environment
12
Page 13 of 29
269
Environmental Science & Technology
3.2.3. Industrial period (1940-2001)
270
Hg concentrations and fluxes in the industrial period are about three times higher compared to the pre-
271
industrial level (1.43 ng L-1 and 0.88 µg m-2 a-1, respectively). This is consistent with peat bog and lake
272
sediment studies, suggesting an Hg enhancement factor of 3-4.3 since pre-industrial times77. Throughout the
273
20th century, Belukha Hg levels are lowest in the 1930s and rise strongly from the 1940s on until culminating
274
in the 1970s. After a distinct decrease in the 1980s, Hg levels in the 1990s and beginning of the 2000s return
275
to their maximum values.
276
The most recent emission inventory24 suggests that emissions from Hg use in consumer products like paint
277
and batteries and in chlor-alkali plants dominated from the 1940s on. Global Hg emissions dropped after the
278
1970s as a consequence of reduced global Hg production67 and air pollution control measures such as
279
elimination of open-air waste burning (including incineration of batteries) in developed countries and
280
capturing of Hg from chlor-alkali plants in sludges, subsequently dumped on land24. This emission estimate is
281
supported by the temporal trend in our data during the industrial period until the end of the 1980s (Figs. 1 and
282
4).
283
With the end of the 20th century coal combustion, artisanal gold mining, and metal production became the
284
major Hg sources24, 78 (see also Fig. 1). Whereas between 1990 and 2005 Hg emissions from these sectors
285
decreased in most parts of the world, Asian emissions grew significantly and dominate recent Hg levels (Fig.
286
1,5). This is mainly caused by increased Asian coal production, doubling between 1983 and
287
200079. Additionally, growing emissions from Hg use in artisanal and small-scale gold mining (ASGM)
288
mainly in Asia, South America, and Africa contributed to rising levels in these continents at the end of the
289
20th century. In China, for instance, 200 small-scale gold mines started operating in the late 1980s80. The
290
increase of the Belukha Hg after the 1980s suggests that during the 1990s and beginning of the 2000s Hg
291
emissions from coal burning and ASGM mainly in Asia outpaced those from commercial Hg use. Our results
292
seem inconsistent with observations of Hg0 at sites in North America and Europe, showing decreases of ~1–
293
2% per year from 1990 to recent8 and with a 20-38% decline in atmospheric Hg concentrations from 1995 to ACS Paragon Plus Environment
13
Environmental Science & Technology
Page 14 of 29
294
2009 at long-term monitoring stations in the Northern and Southern Hemisphere7. However, a closer look
295
reveals that the downward trend is caused by declining concentrations after 2000, whereas Hg levels partially
296
increase in the period 1995-2000, in agreement with the Belukha record. Furthermore, no Asian sites were
297
included in the analysis due to a lack of long-term data from this region. Model calculations of annual surface
298
air Hg0 concentrations in the period 1990-2008 suggests a positive trend in major parts of Asia, but declining
299
levels elsewhere81.
300
3.3. Comparison with other ice-core records
301
Long-term Northern Hemispheric Hg ice core records from Geladaindong (Tibetan Plateau, 20), Mount Logan
302
(Canada, 18), Upper Fremont Glacier (UFG) (USA,
303
22, 62
304
levels is remarkable. Except for the ice core from Upper Fremont Glacier 10-year mean concentrations vary
305
between the respective detection limit and 2-5 ng L-1. These similar levels confirm that the major part of Hg
306
in the atmosphere is gaseous Hg0, transported across long distances and globally distributed due to its long
307
life-time of ~1 year. Unlike Hg, concentration records of aerosol-borne heavy metals having a shorter life-
308
time vary significantly between different regions. Concentrations levels of Pb with a life-time of ~1 week, for
309
example, are at least one order of magnitude higher at Belukha compared to Greenland and Canadian Arctic
310
sites, due to the closer proximity to the source areas44, 82.
311
Ice-core long-term Hg trends are marked by increasing levels until the 1970s, followed by a sharp decrease.
312
Thus, there is growing agreement among ice core records, supported by lake sediment records that emissions
313
from gold/silver mining in the 19th century are minor compared to the 1970s peak, reflecting the height of Hg
314
use in consumer products like paint and batteries and in chlor-alkali plants. This is only different for the
315
Arctic sites, were none of the records shows a pronounced peak in the 1970s. The increase during the end of
316
the 1990s and beginning of the 2000s due to emissions from coal burning and ASGM is captured at the
23, 61
) and Canadian Arctic as well as Greenlandic sites21,
were compared with the Belukha data (Fig. 5). The agreement in the trend and absolute concentration
ACS Paragon Plus Environment
14
Page 15 of 29
Environmental Science & Technology
317
Belukha and the Arctic sites. The record from Mount Logan shows rising annual values between 1993 and
318
199818, whereas other ice core records ended too early to capture recent periods.
319
3.4. Comparison with model results
320
The most recent biogeochemical modelling of atmospheric Hg in the period 1850-201024 and the Belukha ice
321
core record shows a notable agreement (Fig. 4), except the magnitude of the 1880-1930 peak and the most
322
recent period. The discrepancy between the modelled Hg and the ice core data in the 19th century is possibly
323
due to an overestimation of gaseous Hg0 emissions from amalgamation as discussed above. During the most
324
recent period model simulations suggest declining atmospheric Hg concentrations in 1970-2000 and
325
increasing levels after 2000. In contrast, in the Belukha record Hg started rising again around 1990, implying
326
that the influence of recent emissions from regional coal burning and ASGM in Asian countries on
327
atmospheric Hg concentrations can be detected about 10 years earlier in Central Asia compared to the global
328
perspective. This discrepancy might also be explained by uncertainties in emission data, used as input for the
329
biogeochemical models or uncertainties in reservoir exchange constants in the models and dependent on the
330
applied emission data set6,
331
emission estimates with observations from natural archives to better document and understand global trends
332
of atmospheric Hg pollution.
83
, recent trends diverge24. This emphasizes the importance of constraining
333 334
Acknowledgements
335
The authors acknowledge the help of Patrick Ginot, Beat Rufibach (deceased), Martin Lüthi, Henrik Rhyn,
336
Dimitrii N. Kozlov, Sergej Derewstschikow, Vladimir Vashenzev, Andrej Jerjomin (deceased), Veronica
337
Morozova, Alexander Chebotkin, and Igor Karakulko during the ice coring expedition on Belukha glacier.
338
We thank the three anonymous reviewers for their valuable and constructive comments, improving the clarity
339
of the manuscript.
ACS Paragon Plus Environment
15
Environmental Science & Technology
Page 16 of 29
340
Supporting Information
341
Results of the analyses of a certified reference material (Table S1) and information about the Belukha age-
342
depth scale (Figure S1) are shown. This information is available free of charge via the Internet at
343
http://pubs.acs.org.
344 345
References
346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382
(1) Evers, D. C.; Keane, S. E.; Basu, N.; Buck, D. Evaluating the effectiveness of the Minamata Convention on Mercury: Principles and recommendations for next steps. Sci. Tot. Environ. 2016, 569, 888903. (2) Schroeder, W. H.; Munthe, J. Atmospheric mercury - An overview. Atmos. Environ. 1998, 32 (5), 809-822. (3) Chen, L.; Wang, H. H.; Liu, J. F.; Tong, Y. D.; Ou, L. B.; Zhang, W.; Hu, D.; Chen, C.; Wang, X. J. Intercontinental transport and deposition patterns of atmospheric mercury from anthropogenic emissions. Atmos. Chem. Phys. 2014, 14 (18), 10163-10176. (4) Amos, H. M.; Jacob, D. J.; Streets, D. G.; Sunderland, E. M. Legacy impacts of all-time anthropogenic emissions on the global mercury cycle. Global Biogeochem. Cycles 2013, 27 (2), 410-421. (5) AMAP/UNEP United Nations Environment Programme, UNEP Chemicals, and Arctic Monitoring and Assessment Programme. Technical background report for the global mercury assessment 2013. (6) Streets, D. G.; Devane, M. K.; Lu, Z. F.; Bond, T. C.; Sunderland, E. M.; Jacob, D. J. All-Time Releases of Mercury to the Atmosphere from Human Activities. Environ. Sci. Technol. 2011, 45 (24), 1048510491. (7) Slemr, F.; Brunke, E. G.; Ebinghaus, R.; Kuss, J. Worldwide trend of atmospheric mercury since 1995. Atmos. Chem. Phys. 2011, 11 (10), 4779-4787. (8) Zhang, Y. X.; Jacob, D. J.; Horowitz, H. M.; Chen, L.; Amos, H. M.; Krabbenhoft, D. P.; Slemr, F.; St Louis, V. L.; Sunderland, E. M. Observed decrease in atmospheric mercury explained by global decline in anthropogenic emissions. Proc. Nat. Acad. Sci. U.S.A. 2016, 113 (3), 526-531. (9) Sprovieri, F.; Pirrone, N.; Bencardino, M.; D'Amore, F.; Carbone, F.; Cinnirella, S.; Mannarino, V.; Landis, M.; Ebinghaus, R.; Weigelt, A.; et al. Atmospheric mercury concentrations observed at ground-based monitoring sites globally distributed in the framework of the GMOS network. Atmos. Chem. Phys. 2016, 16 (18), 11915-11935. (10) Engstrom, D. R.; Balogh, S. J.; Swain, E. B. History of mercury inputs to Minnesota lakes: Influences of watershed disturbance and localized atmospheric deposition. Limnol. Oceanogr. 2007, 52 (6), 2467-2483. (11) Lockhart, W. L.; Macdonald, R. W.; Outridge, P. M.; Wilkinson, P.; DeLaronde, J. B.; Rudd, J. W. M. Tests of the fidelity of lake sediment core records of mercury deposition to known histories of mercury contamination. Sci. Tot. Environ. 2000, 260 (1-3), 171-180. (12) Muir, D. C. G.; Wang, X.; Yang, F.; Nguyen, N.; Jackson, T. A.; Evans, M. S.; Douglas, M.; Kock, G.; Lamoureux, S.; Pienitz, R.; et al. Spatial Trends and Historical Deposition of Mercury in Eastern and Northern Canada Inferred from Lake Sediment Cores. Environ. Sci. Technol. 2009, 43 (13), 4802-4809. (13) Siegel, F. R.; Kravitz, J. H.; Galasso, J. J. Arsenic and mercury contamination in 31 cores taken in 1965, St. Anna Trough, Kara Sea, Arctic Ocean. Environ. Geol. 2001, 40 (4-5), 528-542. (14) Yang, H. D.; Battarbee, R. W.; Turner, S. D.; Rose, N. L.; Derwent, R. G.; Wu, G. J.; Yang, R. Q. Historical Reconstruction of Mercury Pollution Across the Tibetan Plateau Using Lake Sediments. Environ. Sci. Technol. 2010, 44 (8), 2918-2924. ACS Paragon Plus Environment
16
Page 17 of 29
383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429
Environmental Science & Technology
(15) Allan, M.; Le Roux, G.; Sonke, J. E.; Piotrowska, N.; Streel, M.; Fagel, N. Reconstructing historical atmospheric mercury deposition in Western Europe using: Misten peat bog cores, Belgium. Sci. Tot. Environ. 2013, 442, 290-301. (16) Biester, H.; Bindler, R.; Martinez-Cortizas, A.; Engstrom, D. R. Modeling the past atmospheric deposition of mercury using natural archives. Environ. Sci. Technol. 2007, 41 (14), 4851-4860. (17) Givelet, N.; Roos-Barraclough, F.; Shotyk, W. Predominant anthropogenic sources and rates of atmospheric mercury accumulation in southern Ontario recorded by peat cores from three bogs: comparison with natural "background'' values (past 8000 years). J. Envir. Monit. 2003, 5 (6), 935-949. (18) Beal, S. A.; Osterberg, E. C.; Zdanowicz, C. M.; Fisher, D. A. Ice Core Perspective on Mercury Pollution during the Past 600 Years. Environ. Sci. Technol. 2015, 49 (13), 7641-7647. (19) Fain, X.; Ferrari, C. P.; Dommergue, A.; Albert, M. R.; Battle, M.; Severinghaus, J.; Arnaud, L.; Barnola, J. M.; Cairns, W.; Barbante, C.; et al. Polar firn air reveals large-scale impact of anthropogenic mercury emissions during the 1970s. Proc. Nat. Acad. Sci. U.S.A. 2009, 106 (38), 16114-16119. (20) Kang, S. C.; Huang, J.; Wang, F. Y.; Zhang, Q. G.; Zhang, Y. L.; Li, C. L.; Wang, L.; Chen, P. F.; Sharma, C. M.; Li, Q.; et al. Atmospheric Mercury Depositional Chronology Reconstructed from Lake Sediments and Ice Core in the Himalayas and Tibetan Plateau. Environ. Sci. Technol. 2016, 50 (6), 28592869. (21) Zdanowicz, C. M.; Krummel, E. M.; Poulain, A. J.; Yumvihoze, E.; Chen, J.; Strok, M.; Scheer, M.; Hintelmann, H. Historical variations of mercury stable isotope ratios in Arctic glacier firn and ice cores. Global Biogeochem. Cycles 2016, 30 (9), 1324-1347. (22) Zheng, J. C. Archives of total mercury reconstructed with ice and snow from Greenland and the Canadian High Arctic. Sci. Tot. Environ. 2015, 509-510, 133-144. (23) Schuster, P. F.; Krabbenhoft, D. P.; Naftz, D. L.; Cecil, L. D.; Olson, M. L.; Dewild, J. F.; Susong, D. D.; Green, J. R.; Abbott, M. L. Atmospheric mercury deposition during the last 270 years: A glacial ice core record of natural and anthropogenic sources. Environ. Sci. Technol. 2002, 36 (11), 2303-2310. (24) Horowitz, H. M.; Jacob, D. J.; Amos, H. M.; Streets, D. G.; Sunderland, E. M. Historical Mercury Releases from Commercial Products: Global Environmental Implications. Environ. Sci. Technol. 2014, 48 (17), 10242-10250. (25) Engstrom, D. R.; Swain, E. B. Recent declines in atmospheric mercury deposition in the upper Midwest. Environ. Sci. Technol. 1997, 31 (4), 960-967. (26) Lindeberg, C.; Bindler, R.; Bigler, C.; Rosen, P.; Renberg, I. Mercury pollution trends in subarctic lakes in the northern Swedish mountains. Ambio 2007, 36 (5), 401-405. (27) Lockhart, W. L.; Wilkinson, P.; Billeck, B. N.; Danell, R. A.; Hunt, R. V.; Brunskill, G. J.; Delaronde, J.; St Louis, V. Fluxes of mercury to lake sediments in central and northern Canada inferred from dated sediment cores. Biogeochemistry 1998, 40 (2-3), 163-173. (28) Mast, M. A.; Manthorne, D. J.; Roth, D. A. Historical deposition of mercury and selected trace elements to high-elevation National Parks in the Western US inferred from lake-sediment cores. Atmos. Environ. 2010, 44 (21-22), 2577-2586. (29) Bindler, R.; Renberg, I.; Appleby, P. G.; Anderson, N. J.; Rose, N. L. Mercury Accumulation Rates and Spatial Patterns in Lake Sediments from West Greenland: A Coast to Ice Margin Transect. Environ. Sci. Technol. 2001, 35 (9), 1736-1741. (30) Engstrom, D. R.; Fitzgerald, W. F.; Cooke, C. A.; Lamborg, C. H.; Drevnick, P. E.; Swain, E. B.; Balogh, S. J.; Balcom, P. H. Atmospheric Hg Emissions from Preindustrial Gold and Silver Extraction in the Americas: A Reevaluation from Lake-Sediment Archives. Environ. Sci. Technol. 2014, 48 (12), 6533-6543. (31) Fitzgerald, W. F.; Engstrom, D. R.; Lamborg, C. H.; Tseng, C. M.; Balcom, P. H.; Hammerschmidt, C. R. Modern and historic atmospheric mercury fluxes in northern Alaska: Global sources and Arctic depletion. Environ. Sci. Technol. 2005, 39 (2), 557-568.
ACS Paragon Plus Environment
17
Environmental Science & Technology
430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477
Page 18 of 29
(32) Phillips, V. J. A.; St Louis, V. L.; Cooke, C. A.; Vinebrooke, R. D.; Hobbs, W. O. Increased Mercury Loadings to Western Canadian Alpine Lakes over the Past 150 Years. Environ. Sci. Technol. 2011, 45 (6), 2042-2047. (33) Sun, L. G.; Yin, X. B.; Liu, X. D.; Zhu, R. B.; Xie, Z. Q.; Wang, Y. H. A 2000-year record of mercury and ancient civilizations in seal hairs from King George Island, West Antarctica. Sci. Tot. Environ. 2006, 368 (1), 236-247. (34) Yang, H. D.; Turner, S.; Rose, N. L. Mercury pollution in the lake sediments and catchment soils of anthropogenically-disturbed sites across England. Environmental Pollution 2016, 219, 1092-1101. (35) Olivier, S.; Schwikowski, M.; Brütsch, S.; Eyrikh, S.; Gäggeler, H. W.; Lüthi, M.; Papina, T.; Saurer, M.; Schotterer, U.; Tobler, L.; et al. Glaciochemical investigation of an ice core from Belukha glacier, Siberian Altai. Geophys. Res. Lett. 2003, 30 (19), 2019. (36) Aizen, V. B.; Aizen, E. M.; Joswiak, D. R.; Fujita, K.; Takeuchi, N.; Nikitin, S. A. Climatic and atmospheric circulation pattern variability from ice-core isotope/geochemistry records (Altai, Tien Shan and Tibet). Ann. Glaciol. 2006, 43, 49-60. (37) Henderson, K.; Laube, A.; Gäggeler, H. W.; Olivier, S.; Papina, T.; Schwikowski, M. Temporal variations of accumulation and temperature during the past two centuries from Belukha ice core, Siberian Altai. J. Geophys. Res. Atmos. 2006, 111 (D3), D03104. (38) Olivier, S.; Blaser, C.; Brütsch, S.; Frolova, N.; Gäggeler, H. W.; Henderson, K. A.; Palmer, A. S.; Papina, T.; Schwikowski, M. Temporal variations of mineral dust, biogenic tracers, and anthropogenic species during the past two centuries from Belukha ice core, Siberian Altai. J. Geophys. Res. Atmos. 2006, 111 (D5), D05309. (39) Haefeli, R. Contribution to the movement and the form of ice sheets in the Arctic and Antarctic. J. Glaciol. 1961, 3 (30), 1133-1151. (40) Olivier, S.; Bajo, S.; Fifield, L. K.; Gäggeler, H. W.; Papina, T.; Santschi, P. H.; Schotterer, U.; Schwikowski, M.; Wacker, L. Plutonium from global fallout recorded in an ice core from the Belukha glacier, Siberian Altai. Environ. Sci. Technol. 2004, 38 (24), 6507-6512. (41) Eichler, A.; Olivier, S.; Henderson, K.; Laube, A.; Beer, J.; Papina, T.; Gäggeler, H. W.; Schwikowski, M. Temperature response in the Altai region lags solar forcing. Geophys. Res. Lett. 2009, 36, L01808. (42) Eichler, A.; Brütsch, S.; Olivier, S.; Papina, T.; Schwikowski, M. A 750 year ice core record of past biogenic emissions from Siberian boreal forests. Geophys. Res. Lett. 2009, 36, L18813. (43) Eichler, A.; Tinner, W.; Brütsch, S.; Olivier, S.; Papina, T.; Schwikowski, M. An ice-core based history of Siberian forest fires since AD 1250. Quat. Sci. Rev. 2011, 30 (9-10), 1027-1034. (44) Eichler, A.; Tobler, L.; Eyrikh, S.; Gramlich, G.; Malygina, N.; Papina, T.; Schwikowski, M. Three Centuries of Eastern European and Altai Lead Emissions Recorded in a Belukha Ice Core. Environ. Sci. Technol. 2012, 46 (8), 4323-4330. (45) Eichler, A.; Tobler, L.; Eyrikh, S.; Malygina, N.; Papina, T.; Schwikowski, M. Ice-Core Based Assessment of Historical Anthropogenic Heavy Metal (Cd, Cu, Sb, Zn) Emissions in the Soviet Union. Environ. Sci. Technol. 2014, 48 (5), 2635-2642. (46) Papina, T.; Eyrikh, S. Analytical problems of ultra-low Hg concentrations determination in the precipitation and ice cores, Proceedings of the Second International Symposium on "Mercury in the biosphere: ecological-geochemical aspects." Novosibirsk Institute of Inorganic Chemistry SB RAS, 2015, 288-291. (47) US EPA Method 1631, Revision E: Mercury in water by oxidation, purge and trap, and cold vapor atomic fluorescence spectrometry. In U.S. Environmental Protection Agency, Office of Water, Office of Science and Technology, Engineering and Analysis Division (4303), Washington, D.C., 2002. (48) Ferrari, C. P.; Moreau, A. L.; Boutron, C. F. Clean conditions for the determination of ultra-low levels of mercury in ice and snow samples. Fresenius Journal of Analytical Chemistry 2000, 366 (5), 433-437.
ACS Paragon Plus Environment
18
Page 19 of 29
478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526
Environmental Science & Technology
(49) Eyrikh, S.; Schwikowski, M.; Gäggeler, H. W.; Tobler, L.; Papina, T. First mercury determination in snow and firn from high-mountain glaciers in the Siberian Altai by CV-ICP-MS. Journal De Physique IV 2003, 107, 431-434. (50) Eyrikh, S.; Schwikowski, M.; Gäggeler, H. W.; Tobler, L.; Papina, T. First mercury determination in snow from high-mountain sites in the Siberian Altai and Swiss Alps as reflection of present atmospheric concentrations of Hg. RMZ - Materials and Geoenvironment 2004, 51 (2), 1551-1555. (51) Fu, X. W.; Yang, X.; Lang, X. F.; Zhou, J.; Zhang, H.; Yu, B.; Yan, H. Y.; Lin, C. J.; Feng, X. B. Atmospheric wet and litterfall mercury deposition at urban and rural sites in China. Atmos. Chem. Phys. 2016, 16 (18), 11547-11562. (52) Durnford, D.; Dastoor, A. The behavior of mercury in the cryosphere: A review of what we know from observations. J. Geophys. Res. Atmos. 2011, 116. (53) Lalonde, J. D.; Poulain, A. J.; Amyot, M. The role of mercury redox reactions in snow on snow-to-air mercury transfer. Environ. Sci. Technol. 2002, 36 (2), 174-178. (54) Zhang, Q. G.; Huang, J.; Wang, F. Y.; Mark, L. W.; Xu, J. Z.; Armstrong, D.; Li, C. L.; Zhang, Y. L.; Kang, S. C. Mercury Distribution and Deposition in Glacier Snow over Western China. Environ. Sci. Technol. 2012, 46 (10), 5404-5413. (55) Wu, G. J.; Yao, T. D.; Xu, B. Q.; Tian, L. D.; Zhang, C. L.; Zhang, X. L. Dust concentration and flux in ice cores from the Tibetan Plateau over the past few decades. Tellus Series B-Chemical and Physical Meteorology 2010, 62 (3), 197-206. (56) Huang, J.; Kang, S. C.; Guo, J. M.; Zhang, Q. G.; Xu, J. Z.; Jenkins, M. G.; Zhang, G. S.; Wang, K. Seasonal variations, speciation and possible sources of mercury in the snowpack of Zhadang glacier, Mt. Nyainqentanglha, southern Tibetan Plateau. Sci. Tot. Environ. 2012, 429, 223-230. (57) Loewen, M.; Kang, S.; Armstrong, D.; Zhang, Q.; Tomy, G.; Wang, F. Atmospheric transport of mercury to the Tibetan plateau. Environ. Sci. Technol. 2007, 41 (22), 7632-7638. (58) Frolova, N.; Eyrikh, S.; Papina, T.; Schwikowski, M. Spatial-temporal evaluation of atmosphere mercury pollution in Altai from layer-by-layer analysis of Belukha ice core. Chemistry for Sustainable Development 2008, 16, 227-234. (59) Eyrikh, S.; Eichler, A.; Tobler, L.; Papina, T.; Schwikowski, M. 300 years of mercury emissions recorded in a Belukha ice core, Annual Report, Labor für Radio- und Umweltchemie der Universität Bern und des Paul Scherrer Instituts, 2013, 27. (60) Pyle, D. M.; Mather, T. A. The importance of volcanic emissions for the global atmospheric mercury cycle. Atmos. Environ. 2003, 37 (36), 5115-5124. (61) Chellman, N.; McConnell, J. R.; Arienzo, M.; Pederson, G. T.; Aarons, S. M.; Csank, A. Reassessment of the Upper Fremont Glacier Ice-Core Chronologies by Synchronizing of Ice-Core-Water Isotopes to a Nearby Tree-Ring Chronology. Environ. Sci. Technol. 2017, 51 (8), 4230-4238. (62) Zdanowicz, C.; Kruemmel, E.; Lean, D.; Poulain, A.; Kinnard, C.; Yumvihoze, E.; Chen, J. B.; Hintelmann, H. Pre-industrial and recent (1970-2010) atmospheric deposition of sulfate and mercury in snow on southern Baffin Island, Arctic Canada. Sci. Tot. Environ. 2015, 509, 104-114. (63) Zheng, J. C.; Pelchat, P.; Vaive, J.; Bass, D.; Ke, F. Total mercury in snow and ice samples from Canadian High Arctic ice caps and glaciers: A practical procedure and method for total Hg quantification at low pg g(-1) level. Sci. Tot. Environ. 2014, 468-469, 487-494. (64) Planchon, F. A. M.; Gabrielli, P.; Gauchard, P. A.; Dommergue, A.; Barbante, C.; Cairns, W. R. L.; Cozzi, G.; Nagorski, S. A.; Ferrari, C. P.; Boutron, C. F.; et al. Direct determination of mercury at the subpicogram per gram level in polar snow and ice by ICP-SFMS. J. Anal. At. Spectrom. 2004, 19 (7), 823-830. (65) Cooke, C. A.; Balcom, P. H.; Kerfoot, C.; Abbott, M. B.; Wolfe, A. P. Pre-Colombian Mercury Pollution Associated with the Smelting of Argentiferous Ores in the Bolivian Andes. Ambio 2011, 40 (1), 1825. (66) Hylander, L. D.; Meili, M. The rise and fall of mercury: Converting a resource to refuse after 500 years of mining and pollution. Critical Reviews in Environmental Science and Technology 2005, 35 (1), 1-36. ACS Paragon Plus Environment
19
Environmental Science & Technology
527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573
Page 20 of 29
(67) Hylander, L. D.; Meili, M. 500 years of mercury production: global annual inventory by region until 2000 and associated emissions. Sci. Tot. Environ. 2003, 304 (1-3), 13-27. (68) Nriagu, J. O. Mercury pollution from the past mining of gold and silver in the Americas. Sci. Tot. Environ. 1994, 149 (3), 167-181. (69) Cooke, C. A.; Bindler, R., Lake Sediment Records of Preindustrial Metal Pollution. In DPER Environmental Contaminants: Volume 18: Using natural archives to track sources and long-term trends of pollution, Blais, J. M.; Rosen, M. R.; Smol, J. P., Eds. Springer, New York: 2015, pp 101-120. (70) Eyrikh, S.; Eichler, A.; Tobler, L.; Schwikowski, M. Reflection of mining and metallurgical industry history of Altai in XVIII-XIX centuries in the Belukha glacier ice core. Bulletin AB RGS (Izvestiya AO RGO) 2016, 4 (43), 68-80. (71) Vedernikov, V. V. Amalgamation: Why was there no alternative to conventional silver smelting in the Altai in the first third of the XIX century? Contemporary historical Sibirian studies of the 17th - early 20th centuries: A collection of scientific articles Barnaul 2008, 2, 68-77. (72) Karpenko, Z. G. Mining and metallurgical industry of Western Siberia in 1700-1860. Novosibirsk, 1963, 216. (73) Cooke, C. A.; Hintelmann, H.; Ague, J. J.; Burger, R.; Biester, H.; Sachs, J. P.; Engstrom, D. R. Use and Legacy of Mercury in the Andes. Environ. Sci. Technol. 2013, 47 (9), 4181-4188. (74) Guerrero, S. The history of silver refining in New Spain, 16c to 18c: back to the basics. Hist. Technol. 2016, 32 (1), 2-32. (75) Gerasimova, N. K.; Mytarev, A. A.; Savelieva, L. M. Economic Geography of the Kuzbass. Kemerovo, 1966, 75. (76) Pacyna, J. M., Atmospheric Emissions of Arsenic, Cadmium, Lead and Mercury from High Temperature Processes in Power Generation and Industry. In Chapter 7 in Lead, Mercury, Cadmium and Arsenic in the Environment, Hutchinson, T. C.; Meema, K. M., Eds. SCOPE, 1987. (77) Amos, H. M.; Sonke, J. E.; Obrist, D.; Robins, N.; Hagan, N.; Horowitz, H. M.; Mason, R. P.; Witt, M.; Hedgecock, I. M.; Corbitt, E. S.; et al. Observational and Modeling Constraints on Global Anthropogenic Enrichment of Mercury. Environ. Sci. Technol. 2015, 49 (7), 4036-4047. (78) Pacyna, E. G.; Pacyna, J. M.; Steenhuisen, F.; Wilson, S. Global anthropogenic mercury emission inventory for 2000. Atmos. Environ. 2006, 40 (22), 4048-4063. (79) U.S. Energy Information Administration https://www.eia.gov/todayinenergy/detail.php?id=4210 (80) Lacerda, L. D. Global mercury emissions from gold and silver mining. Water Air Soil Pollut. 1997, 97 (3-4), 209-221. (81) Soerensen, A. L.; Jacob, D. J.; Streets, D. G.; Witt, M. L. I.; Ebinghaus, R.; Mason, R. P.; Andersson, M.; Sunderland, E. M. Multi-decadal decline of mercury in the North Atlantic atmosphere explained by changing subsurface seawater concentrations. Geophys. Res. Lett. 2012, 39, L21810. (82) Grigholm, B.; Mayewski, P. A.; Aizen, V.; Kreutz, K.; Wake, C. P.; Aizen, E.; Kang, S.; Maasch, K. A.; Handley, M. J.; Sneed, S. B. Mid-twentieth century increases in anthropogenic Pb, Cd and Cu in central Asia set in hemispheric perspective using Tien Shan ice core. Atmos. Environ. 2016, 131, 17-28. (83) Wilson, S.; Munthe, J.; Sundseth, K.; Kindbom, K.; Maxson, P.; Pacyna, J. M.; Steenhuisen, F. Updating Historical Global Inventories of Anthropogenic Mercury Emissions to Air; Arctic Monitoring and Assessment Program (AMAP). Oslo, Norway, 2010. (84) Kang, S.; Wang, F.; Morgenstern, U.; Zhang, Y.; Grigholm, B.; Kaspari, S.; Schwikowski, M.; Ren, J.; Yao, T.; Qin, D.; et al. Dramatic loss of glacier accumulation area on the Tibetan Plateau revealed by ice core tritium and mercury records. Cryosphere 2015, 9 (3), 1213-1222. (85) Jitaru, P.; Infante, H. G.; Ferrari, C. P.; Dommergue, A.; Boutron, C. F.; Adams, F. C. Present century record of mercury species pollution in high altitude alpine snow and ice. Journal De Physique IV 2003, 107, 683-686.
574 ACS Paragon Plus Environment
20
Page 21 of 29
575 576
Environmental Science & Technology
Table 1: Compilation of total Hg concentrations (ng L-1) and fluxes (µg m-2 a-1) from different Northern Hemisphere ice-core sites. Given are minimum – maximum/median values or means* of the three different time periods 1680-1850, 1850-1940, 1940-2001.
577 Sampling site, elevation, m a.s.l.,
Hg concentrations, ng L-1
Hg fluxes, µg m-2 a-1
Preindustrial period, 1680-1850
Intermediate period, 1850-1940
Industrial period, 1940-2001
Preindustrial period, 1680-1850
Intermediate period, 1850-1940
Belukha glacier, Siberian Altai, 4062 m a.s.l., 2001
0.07 – 2.9 0.47
0.2 – 8.9 0.89
0.08 – 6.0 1.43
0.04 – 1.8 0.32
0.11 – 1.9 0.53
Mt. Geladaindong, Tibetan Plateau, 5750 m a.s.l., 2005
0.002 – 5.0 0.47
Mount Logan, Yukon, Canada, 5340 m a.s.l., 2001, 2002